If you ever get the chance to go... I highly reccommend it. Watching the events on the television just doesn't do the cars any justice. Either in the speed or the sound departments. Being there is a totally different experience.
When we(my Brother, Father and I) went last year, we were invited into the RocketSports Team garage while they worked on the car. The mechanics fired the car up and started revving the engine. Standing right beside the car(we were only a few inches away) with them blipping on the throttle... the sound just reverberated right through you... could feel it pass through your bones
Was also able to get Paul Tracy's(my favorite CART driver) autograph on a picture my brother took at last years GP and blew up to poster size as a gift for my birthday. He snapped the pic as PT was coming into turn 1 and had locked up the front right tire... so there was a bunch of smoke coming off it.
PT was pretty impressed with the picture.
Going to frame it now... have had it in the package since my bro gave it to me last year. Now that its signed it going up on my wall
